feat(#462): add federation query source routing

apps/gateway/src/federation/client/__tests__/query-source.service.spec.ts

@@ -0,0 +1,255 @@
+import 'reflect-metadata';
+import { describe, expect, it, vi } from 'vitest';
+import type { Db } from '@mosaicstack/db';
+import type { FederationListResponse } from '@mosaicstack/types';
+import {
+  FederationClientError,
+  type FederationClientService,
+} from '../federation-client.service.js';
+import { type QuerySourceError, QuerySourceService } from '../query-source.service.js';
+
+interface TestRow {
+  id: string;
+  title: string;
+}
+
+interface PeerRow {
+  id: string;
+  commonName: string;
+  endpointUrl: string | null;
+  clientKeyPem: string | null;
+  state: 'active' | 'pending' | 'suspended' | 'revoked';
+}
+
+const LOCAL_ROWS: TestRow[] = [
+  { id: 'local-1', title: 'Local One' },
+  { id: 'local-2', title: 'Local Two' },
+];
+
+const PEER_A: PeerRow = {
+  id: 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa',
+  commonName: 'peer-a',
+  endpointUrl: 'https://peer-a.example.com',
+  clientKeyPem: 'sealed-key-a',
+  state: 'active',
+};
+
+const PEER_B: PeerRow = {
+  id: 'bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb',
+  commonName: 'peer-b',
+  endpointUrl: 'https://peer-b.example.com',
+  clientKeyPem: 'sealed-key-b',
+  state: 'active',
+};
+
+const PEER_LOCALHOST: PeerRow = {
+  id: 'cccccccc-cccc-cccc-cccc-cccccccccccc',
+  commonName: 'peer-localhost',
+  endpointUrl: 'https://localhost:3001',
+  clientKeyPem: 'sealed-key-c',
+  state: 'active',
+};
+
+function makeDb(activePeers: PeerRow[]): Db {
+  const orderBy = vi.fn().mockResolvedValue(activePeers);
+  const where = vi.fn().mockReturnValue({ orderBy });
+  const from = vi.fn().mockReturnValue({ where });
+  const select = vi.fn().mockReturnValue({ from });
+
+  return {
+    select,
+    insert: vi.fn(),
+    update: vi.fn(),
+    delete: vi.fn(),
+    transaction: vi.fn(),
+  } as unknown as Db;
+}
+
+function makeFederationClient(
+  list: (
+    peerId: string,
+    resource: string,
+    request: Record<string, unknown>,
+  ) => Promise<FederationListResponse<TestRow>>,
+): FederationClientService {
+  return {
+    list: list as unknown as FederationClientService['list'],
+  } as FederationClientService;
+}
+
+function makeLocalResponse(rows: TestRow[] = LOCAL_ROWS): Promise<FederationListResponse<TestRow>> {
+  return Promise.resolve({ items: rows });
+}
+
+describe('QuerySourceService', () => {
+  it('routes source="local" to the local executor and tags rows as local', async () => {
+    const list = vi.fn(async (): Promise<FederationListResponse<TestRow>> => ({ items: [] }));
+    const service = new QuerySourceService(makeDb([PEER_A]), makeFederationClient(list));
+
+    const result = await service.list<TestRow>({
+      source: 'local',
+      resource: 'tasks',
+      request: { cursor: 'ignored-for-local-test' },
+      local: () => makeLocalResponse(),
+    });
+
+    expect(result).toEqual({
+      items: [
+        { id: 'local-1', title: 'Local One', _source: 'local' },
+        { id: 'local-2', title: 'Local Two', _source: 'local' },
+      ],
+    });
+    expect(list).not.toHaveBeenCalled();
+  });
+
+  it('routes source="federated:<host>" to the matching active peer and tags rows with peer commonName', async () => {
+    const list = vi.fn(
+      async (): Promise<FederationListResponse<TestRow>> => ({
+        items: [{ id: 'remote-1', title: 'Remote One' }],
+      }),
+    );
+    const service = new QuerySourceService(makeDb([PEER_A, PEER_B]), makeFederationClient(list));
+
+    const result = await service.list<TestRow>({
+      source: 'federated:peer-b.example.com',
+      resource: 'tasks',
+      request: { status: 'open' },
+      local: () => makeLocalResponse(),
+    });
+
+    expect(result).toEqual({
+      items: [{ id: 'remote-1', title: 'Remote One', _source: 'peer-b' }],
+    });
+    expect(list).toHaveBeenCalledWith(PEER_B.id, 'tasks', { status: 'open' });
+  });
+
+  it('matches federated hosts by endpoint host including non-default port', async () => {
+    const list = vi.fn(
+      async (): Promise<FederationListResponse<TestRow>> => ({
+        items: [{ id: 'remote-port', title: 'Remote Port' }],
+      }),
+    );
+    const service = new QuerySourceService(makeDb([PEER_LOCALHOST]), makeFederationClient(list));
+
+    const result = await service.list<TestRow>({
+      source: 'federated:localhost:3001',
+      resource: 'tasks',
+      request: {},
+      local: () => makeLocalResponse(),
+    });
+
+    expect(result).toEqual({
+      items: [{ id: 'remote-port', title: 'Remote Port', _source: 'peer-localhost' }],
+    });
+    expect(list).toHaveBeenCalledWith(PEER_LOCALHOST.id, 'tasks', {});
+  });
+
+  it('fans out source="all" to local plus every active outbound peer in parallel and merges tagged rows', async () => {
+    const callOrder: string[] = [];
+    const list = vi.fn(async (peerId: string): Promise<FederationListResponse<TestRow>> => {
+      callOrder.push(`remote-start:${peerId}`);
+      await Promise.resolve();
+      return {
+        items: [{ id: `remote-${peerId.slice(0, 1)}`, title: `Remote ${peerId.slice(0, 1)}` }],
+      };
+    });
+    const service = new QuerySourceService(makeDb([PEER_A, PEER_B]), makeFederationClient(list));
+
+    const result = await service.list<TestRow>({
+      source: 'all',
+      resource: 'tasks',
+      request: { limit: 25 },
+      local: async () => {
+        callOrder.push('local-start');
+        await Promise.resolve();
+        return { items: [{ id: 'local-1', title: 'Local One' }] };
+      },
+    });
+
+    expect(result).toEqual({
+      items: [
+        { id: 'local-1', title: 'Local One', _source: 'local' },
+        { id: 'remote-a', title: 'Remote a', _source: 'peer-a' },
+        { id: 'remote-b', title: 'Remote b', _source: 'peer-b' },
+      ],
+    });
+    expect(list).toHaveBeenCalledTimes(2);
+    expect(callOrder).toEqual([
+      'local-start',
+      `remote-start:${PEER_A.id}`,
+      `remote-start:${PEER_B.id}`,
+    ]);
+  });
+
+  it('marks source="all" as partial and truncated when any subquery returns a cursor', async () => {
+    const list = vi.fn(
+      async (): Promise<FederationListResponse<TestRow>> => ({
+        items: [{ id: 'remote-a', title: 'Remote A' }],
+        nextCursor: 'remote-next',
+      }),
+    );
+    const service = new QuerySourceService(makeDb([PEER_A]), makeFederationClient(list));
+
+    const result = await service.list<TestRow>({
+      source: 'all',
+      resource: 'tasks',
+      request: {},
+      local: () => makeLocalResponse([{ id: 'local-1', title: 'Local One' }]),
+    });
+
+    expect(result).toEqual({
+      items: [
+        { id: 'local-1', title: 'Local One', _source: 'local' },
+        { id: 'remote-a', title: 'Remote A', _source: 'peer-a' },
+      ],
+      _partial: true,
+      _truncated: true,
+    });
+  });
+
+  it('returns _partial=true for source="all" when one peer fails without dropping successful sources', async () => {
+    const list = vi.fn(async (peerId: string): Promise<FederationListResponse<TestRow>> => {
+      if (peerId === PEER_B.id) {
+        throw new FederationClientError({
+          code: 'NETWORK',
+          message: 'peer unavailable',
+          peerId,
+        });
+      }
+      return { items: [{ id: 'remote-a', title: 'Remote A' }] };
+    });
+    const service = new QuerySourceService(makeDb([PEER_A, PEER_B]), makeFederationClient(list));
+
+    const result = await service.list<TestRow>({
+      source: 'all',
+      resource: 'tasks',
+      request: {},
+      local: () => makeLocalResponse([{ id: 'local-1', title: 'Local One' }]),
+    });
+
+    expect(result).toEqual({
+      items: [
+        { id: 'local-1', title: 'Local One', _source: 'local' },
+        { id: 'remote-a', title: 'Remote A', _source: 'peer-a' },
+      ],
+      _partial: true,
+    });
+  });
+
+  it('throws QuerySourceError when a federated host does not match an active outbound peer', async () => {
+    const list = vi.fn(async (): Promise<FederationListResponse<TestRow>> => ({ items: [] }));
+    const service = new QuerySourceService(makeDb([PEER_A]), makeFederationClient(list));
+
+    await expect(
+      service.list<TestRow>({
+        source: 'federated:missing.example.com',
+        resource: 'tasks',
+        request: {},
+        local: () => makeLocalResponse(),
+      }),
+    ).rejects.toMatchObject({
+      name: 'QuerySourceError',
+      code: 'PEER_NOT_FOUND',
+    } satisfies Partial<QuerySourceError>);
+  });
+});

apps/gateway/src/federation/client/index.ts

@@ -11,3 +11,13 @@ export {
   type FederationClientErrorCode,
   type FederationClientErrorOptions,
 } from './federation-client.service.js';
+export {
+  QuerySourceService,
+  QuerySourceError,
+  type QuerySource,
+  type QuerySourceErrorCode,
+  type QuerySourceErrorOptions,
+  type QuerySourceListOptions,
+  type QuerySourceListResponse,
+  type LocalListExecutor,
+} from './query-source.service.js';

apps/gateway/src/federation/client/query-source.service.ts

@@ -0,0 +1,261 @@
+/**
+ * QuerySourceService — gateway query source router (FED-M3-09).
+ *
+ * Accepts the federation query-layer `source` selector and routes list-style
+ * reads to local storage, one federated peer, or all active outbound peers.
+ *
+ * `source: "all"` is intentionally tolerant of per-peer failures: local data
+ * and successful peer responses are returned, and the envelope is marked
+ * `_partial: true`.  Local failures still reject because there is no safe local
+ * fallback and the gateway's own storage is expected to be authoritative.
+ */
+
+import { Inject, Injectable, Logger } from '@nestjs/common';
+import { and, eq, federationPeers, isNotNull, type Db } from '@mosaicstack/db';
+import {
+  SOURCE_LOCAL,
+  tagWithSource,
+  type FederationListResponse,
+  type SourceTag,
+} from '@mosaicstack/types';
+import { DB } from '../../database/database.module.js';
+import { FederationClientService } from './federation-client.service.js';
+
+export type QuerySource = 'local' | 'all' | `federated:${string}`;
+
+export type QuerySourceErrorCode = 'INVALID_SOURCE' | 'PEER_NOT_FOUND';
+
+export interface QuerySourceErrorOptions {
+  code: QuerySourceErrorCode;
+  message: string;
+  source: string;
+}
+
+export class QuerySourceError extends Error {
+  readonly code: QuerySourceErrorCode;
+  readonly source: string;
+
+  constructor(opts: QuerySourceErrorOptions) {
+    super(opts.message);
+    this.name = 'QuerySourceError';
+    this.code = opts.code;
+    this.source = opts.source;
+  }
+}
+
+export type LocalListExecutor<T extends object> = () => Promise<FederationListResponse<T> | T[]>;
+
+export interface QuerySourceListOptions<T extends object> {
+  source: QuerySource;
+  resource: string;
+  request?: Record<string, unknown>;
+  local: LocalListExecutor<T>;
+}
+
+export type QuerySourceListResponse<T extends object> = FederationListResponse<T & SourceTag>;
+
+interface OutboundPeer {
+  id: string;
+  commonName: string;
+  endpointUrl: string;
+}
+
+interface TaggedList<T extends object> {
+  items: Array<T & SourceTag>;
+  partial: boolean;
+  truncated: boolean;
+  nextCursor?: string;
+}
+
+@Injectable()
+export class QuerySourceService {
+  private readonly logger = new Logger(QuerySourceService.name);
+
+  constructor(
+    @Inject(DB) private readonly db: Db,
+    @Inject(FederationClientService) private readonly federationClient: FederationClientService,
+  ) {}
+
+  async list<T extends object>(
+    options: QuerySourceListOptions<T>,
+  ): Promise<QuerySourceListResponse<T>> {
+    const request = options.request ?? {};
+
+    if (options.source === 'local') {
+      const local = await this.runLocal(options.local);
+      return this.toResponse(this.tagList(local, SOURCE_LOCAL));
+    }
+
+    if (options.source === 'all') {
+      return this.listAll(options.resource, request, options.local);
+    }
+
+    if (options.source.startsWith('federated:')) {
+      const host = options.source.slice('federated:'.length).trim();
+      if (!host) {
+        throw new QuerySourceError({
+          code: 'INVALID_SOURCE',
+          message: 'Federated source must include a host after federated:',
+          source: options.source,
+        });
+      }
+
+      const peer = await this.findPeerByHost(host, options.source);
+      const remote = await this.federationClient.list<T>(peer.id, options.resource, request);
+      return this.toResponse(this.tagList(remote, peer.commonName));
+    }
+
+    throw new QuerySourceError({
+      code: 'INVALID_SOURCE',
+      message: `Unsupported query source: ${options.source}`,
+      source: options.source,
+    });
+  }
+
+  private async listAll<T extends object>(
+    resource: string,
+    request: Record<string, unknown>,
+    local: LocalListExecutor<T>,
+  ): Promise<QuerySourceListResponse<T>> {
+    const peers = await this.listActiveOutboundPeers();
+
+    const localPromise = this.runLocal(local).then((response) =>
+      this.tagList(response, SOURCE_LOCAL),
+    );
+    const remotePromises = peers.map(async (peer: OutboundPeer): Promise<TaggedList<T> | null> => {
+      try {
+        const response = await this.federationClient.list<T>(peer.id, resource, request);
+        return this.tagList(response, peer.commonName);
+      } catch (error: unknown) {
+        this.logger.warn(
+          `Federated query to peer ${peer.commonName} (${peer.id}) failed; returning partial all-source response: ${
+            error instanceof Error ? error.message : String(error)
+          }`,
+        );
+        return null;
+      }
+    });
+
+    const [localResult, ...remoteResults] = await Promise.all([localPromise, ...remotePromises]);
+    const successfulRemoteResults = remoteResults.filter(
+      (result: TaggedList<T> | null): result is TaggedList<T> => result !== null,
+    );
+    const allResults = [localResult, ...successfulRemoteResults];
+    const peerFailure = successfulRemoteResults.length !== peers.length;
+
+    return this.mergeTaggedLists(allResults, peerFailure);
+  }
+
+  private async runLocal<T extends object>(
+    local: LocalListExecutor<T>,
+  ): Promise<FederationListResponse<T>> {
+    const response = await local();
+    if (Array.isArray(response)) {
+      return { items: response };
+    }
+    return response;
+  }
+
+  private tagList<T extends object>(
+    response: FederationListResponse<T>,
+    source: string,
+  ): TaggedList<T> {
+    return {
+      items: tagWithSource(response.items, source),
+      partial: response._partial === true,
+      truncated: response._truncated === true || response.nextCursor !== undefined,
+      nextCursor: response.nextCursor,
+    };
+  }
+
+  private mergeTaggedLists<T extends object>(
+    lists: Array<TaggedList<T>>,
+    peerFailure: boolean,
+  ): QuerySourceListResponse<T> {
+    const items = lists.flatMap((list: TaggedList<T>) => list.items);
+    const partial =
+      peerFailure ||
+      lists.some((list: TaggedList<T>) => list.partial || list.nextCursor !== undefined);
+    const truncated = lists.some((list: TaggedList<T>) => list.truncated);
+
+    const response: QuerySourceListResponse<T> = { items };
+    if (partial) {
+      response._partial = true;
+    }
+    if (truncated) {
+      response._truncated = true;
+    }
+    return response;
+  }
+
+  private toResponse<T extends object>(tagged: TaggedList<T>): QuerySourceListResponse<T> {
+    const response: QuerySourceListResponse<T> = {
+      items: tagged.items,
+    };
+    if (tagged.nextCursor !== undefined) {
+      response.nextCursor = tagged.nextCursor;
+    }
+    if (tagged.partial) {
+      response._partial = true;
+    }
+    if (tagged.truncated) {
+      response._truncated = true;
+    }
+    return response;
+  }
+
+  private async findPeerByHost(sourceHost: string, source: string): Promise<OutboundPeer> {
+    const host = normalizeHost(sourceHost);
+    const peers = await this.listActiveOutboundPeers();
+    const peer = peers.find((candidate: OutboundPeer) => {
+      const commonName = normalizeHost(candidate.commonName);
+      const endpointHosts = endpointHostKeys(candidate.endpointUrl).map((endpointHost: string) =>
+        normalizeHost(endpointHost),
+      );
+      return commonName === host || endpointHosts.includes(host);
+    });
+
+    if (!peer) {
+      throw new QuerySourceError({
+        code: 'PEER_NOT_FOUND',
+        message: `No active outbound federation peer matches source ${source}`,
+        source,
+      });
+    }
+
+    return peer;
+  }
+
+  private async listActiveOutboundPeers(): Promise<OutboundPeer[]> {
+    const rows = await this.db
+      .select({
+        id: federationPeers.id,
+        commonName: federationPeers.commonName,
+        endpointUrl: federationPeers.endpointUrl,
+      })
+      .from(federationPeers)
+      .where(
+        and(
+          eq(federationPeers.state, 'active'),
+          isNotNull(federationPeers.endpointUrl),
+          isNotNull(federationPeers.clientKeyPem),
+        ),
+      )
+      .orderBy(federationPeers.commonName);
+
+    return rows.filter((row): row is OutboundPeer => typeof row.endpointUrl === 'string');
+  }
+}
+
+function normalizeHost(host: string): string {
+  return host.trim().toLowerCase();
+}
+
+function endpointHostKeys(endpointUrl: string): string[] {
+  try {
+    const url = new URL(endpointUrl);
+    return Array.from(new Set([url.host, url.hostname].filter((host: string) => host.length > 0)));
+  } catch {
+    return [];
+  }
+}

apps/gateway/src/federation/federation.module.ts

@@ -5,7 +5,7 @@ import { EnrollmentController } from './enrollment.controller.js';
 import { EnrollmentService } from './enrollment.service.js';
 import { FederationController } from './federation.controller.js';
 import { GrantsService } from './grants.service.js';
-import { FederationClientService } from './client/index.js';
+import { FederationClientService, QuerySourceService } from './client/index.js';
 import { FederationAuthGuard } from './server/index.js';
 
 @Module({
@@ -16,6 +16,7 @@ import { FederationAuthGuard } from './server/index.js';
     EnrollmentService,
     GrantsService,
     FederationClientService,
+    QuerySourceService,
     FederationAuthGuard,
   ],
   exports: [
@@ -23,6 +24,7 @@ import { FederationAuthGuard } from './server/index.js';
     EnrollmentService,
     GrantsService,
     FederationClientService,
+    QuerySourceService,
     FederationAuthGuard,
   ],
 })